1. Field of the Invention
This invention relates to a laryngeal mask and method for making such a mask. Specifically, this invention relates to a laryngeal mask with a sanitary, air-tight seal between the dome and tubular cuff that form the mask.
2. Description of Related Art
Laryngeal masks are well known and are commonly used by medical and emergency medical personnel to intubate an unconscious patient for anesthetic and ventilation purposes. A laryngeal mask is inserted into the throat or pharynx of an unconscious patient, such as an accident victim. The laryngeal mask forms a seal around the laryngeal inlet and prevents the epiglottis from blocking the lumen. The laryngeal mask provides an open airway to permit the unconscious patient to breathe and be provided anesthesia.
Laryngeal masks are made by numerous manufacturers and have similar structures for the basic components. These manufacturers use standard terminology for the common components of these devices.
Typically, the basic components of a laryngeal mask include a dome, an airway tube or shaft, and a cuff or rim. The dome is a teardrop-shaped, semi-rigid member wherein the more angular portion of the teardrop shape provides the distal or leading edge for insertion into a patient's larynx. A rigid, yet flexible, tube is inserted into an orifice in the proximal portion of the dome and projects from this rounded portion of the dome. The flexible tube is of sufficient length to traverse a curve or angle from the larynx of a patient to a point outward from the patient's mouth. An inflatable cuff encircles the periphery of the dome and is made of soft, flexible material. When the dome is positioned in the larynx of the patient, the cuff is inflated and forms a seal with the surrounding tissue in the upper esophageal sphincter, pyriform fossae, and esophageal inlet to secure the laryngeal mask in place and to ensure that the internal lumen of the mask is positioned over the laryngeal inlet. Various sizes of laryngeal airway devices are available to accommodate different sizes of patients which include both children and adults. It is desirable that the laryngeal mask be constructed of medical-grade materials that can withstand repeated autoclaving to allow repeated use of the laryngeal mask device. Lesser medical-grade materials can be used for single-use or “disposable” laryngeal mask devices.
The industry strives to improve these individual components as well as the collateral components used in these devices. Collateral components include inflation tubes for the cuff, devices for inserting the laryngeal mask without damaging nerve or other structures, and similar components.
U.S. Pat. No. 5,297,547 to Brain discloses a laryngeal mask construction. The improvement of this patent focuses on “an inflatable ring configured, upon inflation, to establish a peripheral seal around a patient's laryngeal inlet. Installation (insertion) is made in the fully deflated state, wherein the structural relation between the body of the mask and the inflatable ring is such that the deflated ring surfaces become tightly opposed to each other so as to form a thin flange which peripherally surrounds the body of the mask and is concave on the posterior side of the mask; the concave flange effectively displaces all ring material away from the aperture of the mask, in the manner of the upturned brim of a hat.” The invention of this patent approached this problem by placing an excess or bead of filler in the V-shaped area formed between the body (dome) and ring (cuff) of the device. The excess filler enables body stiffness to extend preferentially over posterior material of the ring. This excess bead of filler, however, forms two creases within the narrow V-shaped area wherein contaminants and/or microbes can collect.
The industry lacks a sanitary means and a method for manufacturing a secure air-tight seal between the cuff or tubular structure and dome of laryngeal masks wherein the flexible wall of the cuff is buttressed such that, when deflated, it forms a shape or geometry that facilitates the insertion of the laryngeal mask into the throat of a patient.
The industry also lacks a method for making a secure air-tight seal between the cuff and dome of a laryngeal mask which does not require a protrusion above the seal of continuous filler material to form a buttress for the cuff.